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            <div><h4 class="title">
                <a name="asio.overview.cpp2011.chrono"></a><a class="link" href="chrono.html" title="Chrono">Chrono</a>
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    <p>
        Asio provides timers based on the <code class="computeroutput"><span class="identifier">std</span><span
            class="special">::</span><span class="identifier">chrono</span></code>
        facilities via the <a class="link" href="../../reference/basic_waitable_timer.html"
                              title="basic_waitable_timer">basic_waitable_timer</a>
        class template. The typedefs <a class="link" href="../../reference/system_timer.html" title="system_timer">system_timer</a>,
        <a class="link" href="../../reference/steady_timer.html" title="steady_timer">steady_timer</a> and <a
            class="link" href="../../reference/high_resolution_timer.html" title="high_resolution_timer">high_resolution_timer</a>
        utilise the standard clocks <code class="computeroutput"><span class="identifier">system_clock</span></code>,
        <code class="computeroutput"><span class="identifier">steady_clock</span></code> and <code
            class="computeroutput"><span class="identifier">high_resolution_clock</span></code> respectively.
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    <p>
        Support for the <code class="computeroutput"><span class="identifier">std</span><span
            class="special">::</span><span class="identifier">chrono</span></code> facilities is automatically enabled
        for <code class="literal">g++</code> 4.6 and later, when the <code class="literal">-std=c++0x</code>
        or <code class="literal">-std=gnu++0x</code> compiler options are used. (Note that,
        for <code class="literal">g++</code>, the draft-standard <code class="computeroutput"><span class="identifier">monotonic_clock</span></code>
        is used in place of <code class="computeroutput"><span class="identifier">steady_clock</span></code>.)
        Support may be disabled by defining <code class="computeroutput"><span class="identifier">ASIO_DISABLE_STD_CHRONO</span></code>,
        or explicitly enabled for other compilers by defining <code class="computeroutput"><span class="identifier">ASIO_HAS_STD_CHRONO</span></code>.
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    <p>
        When standard <code class="computeroutput"><span class="identifier">chrono</span></code> is
        unavailable, Asio will otherwise use the Boost.Chrono library. The <a class="link"
                                                                              href="../../reference/basic_waitable_timer.html"
                                                                              title="basic_waitable_timer">basic_waitable_timer</a>
        class template may be used with either.
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            <div class="copyright-footer">Copyright © 2003-2022 Christopher M. Kohlhoff<p>
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